Surgical instrument capable of disassembly

ABSTRACT

A surgical instrument which easily disassembles for sterilization comprises an inner rod coaxially disposed in a hollow tube with a handle at one end of the rod and a working tip at the other end. The handle is detachably interconnected to the inner rod and the inner rod is detachably interconnected to the hollow tube by the cooperation of at least one locking pin secured to the inner rod and a locking tab formed on the inner surface of the hollow tube.

This is a continuation-in-part of application Ser. No. 08/093,477 filedJul. 19, 1993, now U.S. Pat. No. 5,336,238.

BACKGROUND OF THE INVENTION

Up until recently, most abdominal and thoracic procedures required majorincisions in order to provide an ability to observe the body cavity andperform any necessary diagnosis and treatment. This invention relatesgenerally to surgical instruments for use in minimally invasive surgicalprocedures. In general, instruments used in these procedures are of theclosed shaft variety. Since these instruments usually cannot bedisassembled, complete sterilization is not possible because microscopicpockets of tissue and blood are often left on the instrument even aftercompletion of accepted sterilization procedures.

In order to insure complete sterilization of a closed shaft surgicalinstrument, the instrument must essentially be capable of disassemblyinto its major components so that the resulting openings are ofsufficient magnitude to accept cleaning brushes. This insures that allsurfaces of the instrument are exposed to the particular sterilizationmedium and any concern that the instrument is not thoroughly sterilizedis thereby eliminated.

SUMMARY OF THE INVENTION

By this invention, a surgical instrument is provided and comprises aninner rod coaxially disposed within a hollow tube and which has aworking tip at the distal end and a handle at the proximal end andwherein the handle is detachably interconnected to the inner rod. Also,at least one locking pin is secured to the distal end of the inner rodand is capable of being interlocked with a locking tab formed on theinner surface of the hollow tube.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings,

FIG. 1 is a perspective view of a surgical instrument capable ofdisassembly according to this invention;

FIG. 2 is a perspective view of the instrument handle;

FIG. 3 is a perspective view of the handle in disassembled condition;

FIG. 4 is a perspective view of the handle release means;

FIG. 5 is a perspective view of the means for interconnecting the handleand the inner rod;

FIG. 6 is a cross-sectional view taken along the line 6--6 in FIG. 4;

FIGS. 7 and 8 are perspective views of the distal end of the instrument;

FIG. 9 is a cross-sectional view taken along the line 9--9 in FIG. 7;

FIG. 10 is a perspective view of the instrument in disassembledcondition;

FIG. 11 is a perspective view of an alternative embodiment of theinstrument;

FIG. 12 is a perspective view of the alternative handle release means;

FIG. 13 is a perspective view of the alternative means forinterconnecting the handle and the inner rod;

FIG. 14 is a cross-sectional view of the alternative handle releasemeans;

FIG. 15 is an enlarged cross-sectional view of a portion of thealternative means for interconnecting the handle and the inner rod;

FIG. 16 is a cross-sectional view of the alternative means forinterconnecting the outer hollow tube and the inner rod;

FIG. 17 is a view taken along the line 17--17 in FIG. 16; and

FIG. 18 is an enlarged cross-sectional view of the alternative lockingpin and locking tab.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the drawings, the numeral 1 designates the outer hollow tube of thesurgical instrument and the numeral 2 identifies the inner rod which haslocking element 3 disposed at one end thereof. The working tip of theinstrument is disposed at the distal end thereof and comprises jaws 4and 5 which are opened and closed by means of linkage mechanism 6, as iswell known.

Disposed at the proximal end of the instrument and secured to hollowtube 1 is rotation knob 7. In order to facilitate a 360 degree rotationof jaws 4 and 5, rotation knob 7 is pivotally mounted on handle element8.

Handle element 9 is detachably connected to handle element 8 by lockingmeans best shown in FIG. 6. More specifically, the locking meanscomprises closed rings 10 and 11 integrally formed on handle element 8and partially closed ring 12 integrally formed on handle element 9. Knob13 is biased outwardly of the handle means or to the right, as viewed inFIG. 6, by means of compression spring 14. Of course, knob 13 would alsobe operable if disposed on the opposite side of the handle means.Attached to knob 13 is a locking rod which comprises an inner portion 15which is of smaller diameter than associated outer portion 16. Retainingpin 17 is secured on the end of the locking rod remote from knob 13 andacts to prevent the locking rod from disengagement from the instrumenthandle means.

As best shown in FIG. 5, means is provided to interconnect inner rod 2and handle element 9. Specifically, inner rod 2 extends through aperture18 of handle element 8 and forms an operably interconnected relationshipwith respect to handle element 9 by the interlocked disposition oflocking element 3 being disposed in slot 19. Of course, operation ofhandles 8 and 9, in known manner, results in the activation of linkagemechanism 6 thereby causing jaws 4 and 5 to open and close as desired.

As is well known, monopolar post 20 is formed on the upper surface ofhandle element 8 at the proximal end of the instrument. Also, in orderto improve the comfort and operability of the instrument, the handleitself is made of an ergonomic configuration.

According to this invention, inner rod 2 and the associated working tipof the instrument are disjointably connected to hollow tube 1 by meansof a collet mechanism. Specifically, collet 21 is rotatable about innerrod 2 independently of hollow tube 1 and comprises bevelled surface 22at one end thereof. Externally threaded end 23 of attachment housing 24is engageable with internal threads formed on the distal end of hollowtube 1. As best shown in FIG. 9, locking pins 25 and 26 are attached tothe housing for linking mechanism 6 in a spring-like fashion and areprovided, respectively, with notches 27 and 28. In the assembledinstrument, locking pins 25 and 26 are disposed in slotted openingsformed in attachment housing 24 such that notches 27 and 28 engageattachment housing 24.

In order to disassemble the fully assembled instrument, as shown in FIG.1, into the fully disassembled instrument, as shown in FIG. 10,initially knob 13 is pushed inwardly of the handle as indicated by arrow29 in FIG. 2. This causes the smaller diameter portion 15 of the lockingrod to move to the left, as viewed in FIG. 6, thus allowing the opensegment of ring 12 to slip past portion 15 which results in theseparation of handle elements 8 and 9. Simultaneously with theseparation of handle elements 8 and 9, locking element 3 is maneuveredout of slot 19, as best viewed in FIG. 5.

Following this operation, collet 21 is manually pushed toward the distalend of the instrument, as indicated by arrow 30 in FIG. 9, so as tocause the ends of locking pins 25 and 26 to slide along bevelled surface22 of collet 21 thereby compressing locking pins 25 and 26 inwardly withrespect to inner rod 2 a sufficient distance to allow notches 27 and 28to disengage attachment housing 24. Inner rod 2 and the associatedworking tip of the instrument can then be easily disassembled wherebylocking element 3 is withdrawn initially through aperture 18 and theninner rod 2 is pulled all the way through hollow tube 1. The instrumentis then disposed in a disassembled condition as shown in FIG. 10.

Following disassembly, the individual elements of the instrument areconveniently and thoroughly sterilized by means of acceptedsterilization procedures. The instrument is then reassembled byinserting inner rod 2 through hollow tube 1 and aperture 18 whereinlocking element 3 is simply inserted into slot 19. Knob 13 is thendepressed thereby allowing ring 12 to be positioned around portion 15 ofthe locking rod. Simultaneously with this operation, locking pins 25 and26 are interlocked with attachment housing 24 respectively by means ofnotches 27 and 28. When knob 13 is released, outer portion 16 entersring 12 and is of sufficiently large diameter to prevent disengagementfrom the open segment of ring 12 so as to secure the handle in acompletely assembled condition whereby the instrument is ready for reusein an appropriate surgical procedure.

FIGS. 11-18 depict an alternative embodiment of the surgical instrumentshown in FIGS. 1-10. With particular reference to FIGS. 11 and 12, thenumeral 101 designates the outer hollow tube of the surgical instrumentand the numeral 102 identifies the inner rod which has locking element103 disposed at one end thereof. The working tip of the instrument isdisposed at the distal end thereof and comprises jaws 104 and 105 whichare opened and closed by means of linkage mechanism 106. Disposed at theproximal end of the instrument and secured to hollow tube 101 isrotation knob 107. Handle elements 108 and 109 are provided and areinterconnected by locking means best shown in FIGS. 13-15. Also, handleelement 109 is offset approximately 30 degrees in order to improve thecomfort and operability of the instrument.

Handle locking means for the alternative embodiment of the instrumentcomprises closed rings 110 and 111 which are integrally formed on handleelement 108 together with partially closed ring 112 integrally formed onhandle element 109. Knob 113 is biased outwardly of the handle means orto the left, as viewed in FIG. 14, by means of compression spring 114.As discussed in connection with knob 13, knob 113 would also be operableif disposed on the opposite side of the handle means. Attached to knob113 is a locking rod which comprises an inner portion 115 which is ofsmaller diameter than associated outer portion 116. Retaining pin 117 issecure on the end of the locking rod remote from knob 113 and acts toprevent disengagement of the locking rod from the instrument handlemeans. According to the alternative embodiment of this invention, ring112 is provided with bevelled surface 112a as best viewed in FIG. 15.

Also according to the alternative embodiment of the invention, inner rod102 and the associated working tip of the instrument are disjointablyconnected to hollow tube 101 by means similar to that shown anddescribed in connection with FIGS. 7-9. More specifically and as bestshown in FIGS. 16-18, locking pins 125 and 126 are attached to thehousing for linkage mechanism 106 in a spring-like fashion and areprovided, respectively, with protuberances 127 and 128. It has beenfound that the optimum metallurgical compound for locking pins 125 and126 is steel 420 heat treated. Protuberances 127 and 128 are shaped in arounded configuration, as best shown in FIG. 18, in order to facilitateseparation of hollow tube 101 and inner rod 102. Finally, locking tabs129 and 130 are integrally formed on the inner surface of outer hollowtube 101.

In order to assemble the instrument depicted in FIGS. 11-18, inner rod102 is slipped into hollow tube 101 and locking element 103 is insertedinto slot 119. Then with handle element 108 and associated locking meansdisposed as shown in FIG. 14 and with inner surface 116a of enlargedportion 116 spaced from the adjacent surface 110a of closed ring 110,ring 112 is simply inserted into the gap between surfaces 110a and 116a.As ring 112 moves into position around smaller diameter portion 115 bymeans of its open segment, the locking rod is progressively forced tothe right to an increasing degree by means of bevelled edge 112a. Then,when ring 112 is fully seated around the locking rod, larger diameterportion 116 is caused to move to the left by means of compression spring114 causing ring 112 to snap into a locked disposition around outerportion 116. By this means, handle elements 108 and 109 areautomatically locked together without having to manipulate knob 113.

Generally simultaneously with this operation, inner rod 102 ismaneuvered into an interlocked relation with outer hollow tube 101 bymeans of protuberances 127 and 128 of locking pins 125 and 126 whichform an interlocked relationship, respectively, with locking tabs 129and 130 integrally formed on the inner surface of outer hollow tube 101.The instrument is then disposed in a fully assembled operationalcondition as shown in FIG. 11.

In order to disassemble the fully assembled instrument, it is simplynecessary to manually press knob 113 inwardly so as to allow ring 112 todisengage smaller diameter portion 115 of the locking rod through theopen segment of ring 112 and simultaneously locking element 103 isremoved from slot 119. Then the user must simply grasp the distal end ofthe instrument around the housing for linkage mechanism 106 such thatpressure is applied to the instrument in an imaginary plane intersectinglocking pins 125 and 126. Due to the spring-like nature of locking pins125 and 126 and since the section of inner rod 102 adjacent locking pins125 and 126 is of smaller diameter than the remainder of inner rod 102,this pressure will cause one of the locking pins to rotate inwardlytoward the axis of inner rod 102. Since protuberances 127 and 128 arerounded, the locking pin which did not rotate into disengagement iseasily caused to disengage its respective locking tab whereby inner rod102 is then manually pulled outwardly through hollow tube 101.

Following disassembly, sterilization of the instrument components isundertaken. Then the alternative embodiment of the instrument isreassembled by inserting inner rod 102 into outer hollow tube 101.Locking element 103 is inserted into slot 119 and simultaneously lockingpins 125 and 126 form an interlocked relationship with locking tabs 129and 130, respectively, and ring 112 is automatically snapped intoposition around larger diameter portion 116 of the locking rod.

We claim:
 1. A surgical instrument comprising a hollow tube having alongitudinal axis, an inner rod having proximal and distal ends andextending through said hollow tube, handle means for impartingreciprocal movement to said inner rod relative to said hollow tube, aworking tip attached to said distal end, said handle means comprising apair of handles, a locking rod engageable with said handle means andcomprising inner and outer portions, one of said portions being ofsmaller diameter than the other of said portions, and one of saidhandles being engageable with respect to said locking rod by means of aring attached to said handle, said ring having a gap, the width of saidgap being greater than the diameter of the one, smaller portion of saidlocking rod and being smaller than the diameter of the other, largerportion of said locking rod, said ring being beveled such that thethickness of said ring is narrowest at an outer edge thereof adjacentthe gap.
 2. A surgical instrument according to claim 1 wherein thelarger portion of said locking rod is engageable with the gapped ring byway of a center hole thereof.